Uterine Inversion Case File

Uterine Inversion Case File

Eugene C. Toy, MD, Patti Jayne Ross, MD, Benton Baker III, MD, John C. Jennings, MD

CASE 3

After a 4-hour labor, a 31-year-old G4P3 woman undergoes an uneventful vaginal delivery of a 7 lb 8 oz infant over an intact perineum. During her labor, she is noted to have mild variable decelerations and accelerations that increase 20 beats per minute (bpm) above the baseline heart rate. At delivery, the male baby has Apgar scores of 8 at 1 minute, and 9 at 5 minute. Slight lengthening of the cord occurs after 28 minutes along with a small gush of blood per vagina. As the placenta is being delivered, a shaggy, reddish, bulging mass is noted at the introitus around the placenta.

» What is the most likely diagnosis?

» What is the most likely complication to occur in this patient?

ANSWER TO CASE 3:

Uterine Inversion                                                        

Summary: A 31-year-old G4P3 woman has a normal vaginal delivery of her baby; after slight lengthening of the cord, a reddish mass is noted bulging in the introitus.

• Most likely diagnosis: Uterine inversion.
• Most likely complication: Postpartum hemorrhage.

ANALYSIS

Objectives

1. Know the signs of spontaneous placental separation.
2. Recognize the clinical presentation of uterine inversion.
3. Understand that the most common cause of uterine inversion is undue traction of the cord before placental separation.

Considerations

This patient’s history reveals that the first and second stages of labor are normal. The third stage of labor (placental delivery) reaches close to the upper limits of normal. There is evidence for partial placental separation, but there were not clear signs of complete placental separation such as lengthening of the cord. The four signs of placental separation are (1) gush of blood, (2) lengthening of the cord, (3) globular and firm shape of the uterus, and (4) the uterus rises up to the anterior abdominal wall. In this case, although there is not good evidence for placental separation, traction on the cord is exerted, which results in an inverted uterus. The reddish bulging mass noted adjacent to the placenta is the endometrial surface; hence, the mass will have a shaggy appearance and be all around the placenta. Other masses and/ or organs may at times prolapse, such as vaginal or cervical tissue, but these will have a smooth appearance.

APPROACH TO:

Inverted Uterus                                                           

DEFINITIONS

ACTIVE MANAGEMENT OF THIRD STAGE OF LABOR: Maneuvers that attempt to facilitate delivery of the placenta to promote uterine contractions and reduce blood loss.

PHYSIOLOGIC MANAGEMENT OF THIRD STAGE OF LABOR: Allowing the natural separation of the placenta before taking any intervention.

THIRD STAGE OF LABOR: From delivery of infant to the delivery of the placenta (upper limit of normal is 30 minutes).

ABNORMALLY RETAINED PLACENTA: Third stage of labor that has exceeded 30 minutes.

UTERINE INVERSION: A “turning inside out” of the uterus; whereupon the fundus of the uterus moves through the cervix, into the vagina (Figure 3– 1).

SIGNS OF PLACENTAL SEPARATION: Cord lengthening, gush of blood, globular uterine shape, and uterus lifting up to the anterior abdominal wall.

Figure 3–1. Inverted uterus. Uterine inversion can occur when excessive umbilical cord traction is

exerted on a fundally implanted, unseparated placenta (A). Upon recognition, the operator attempts

to reposition the inverted uterus using cupped fingers (B).

CLINICAL APPROACH

After a vaginal delivery, 95% of women experience spontaneous placenta separation within 30 minutes. Because the uterus and placenta are no longer joined, the placenta is usually in the lower segment of the uterus, just inside the cervix, and the uterus is often contracted. The umbilical cord lengthens due to the placenta having dropped into the lower portion of the uterus. The gush of blood represents bleeding from the placental bed, usually coinciding with placental separation. If the placenta has not separated, excessive force on the cord may lead to uterine inversion. Massive hemorrhage usually results; thus, in this situation, the practitioner must be prepared for rapid volume replacement. Although it was classically taught by some that the shock was out of proportion to the actual amount of blood loss, this is not the case. In other words, the shock is due to massive hemorrhage.

The best method of averting a uterine inversion is to await spontaneous separation of the placenta from the uterus before placing traction on the umbilical cord. Even after one or two signs of placental separation are present, the operator should be cautious not to put undue tension on the cord. At times, part of the placenta may separate, revealing the gush of blood, but the remaining attached placenta may induce a uterine inversion or traumatic severing of the cord. The grand-multiparous patient with the placenta implanted in the fundus (top of uterus) is at particular risk for uterine inversion. A placenta accreta, an abnormally adherent placenta, is also a risk factor.

TREATMENT

With the diagnosis of an inverted uterus, immediate assistance—including that of an anesthesiologist—is essential because a uterine relaxation anesthetic agent, such as halothane (for uterine replacement), and/or emergency surgery may be necessary. If the placenta has already separated, the recently inverted uterus may sometimes be replaced by using the gloved palm and cupped fingers. Two intravenous lines should be started as soon as possible and preferably prior to placental separation, since profuse hemorrhage may follow placental removal. Terbutaline or magnesium sulfate can also be utilized to relax the uterus if necessary prior to uterine replacement. Upon replacing the uterine fundus to the normal location, the relaxation agents are stopped, and then uterotonic agents, such as oxytocin, are given to prevent re-inversion and also to slow down the bleeding. Placement of the clinician’s fist inside the uterus to maintain the normal structure of the uterus may help to prevent re-inversion.

Note: Even with optimal treatment of uterine inversion, hemorrhage is almost a certainty.

CURRENT CONTROVERSY

There is robust debate about whether active management or physiologic management of the third stage of labor is best. Table 3– 1 shows the differences between these two interventions. In several studies, active management slightly reduces the incidence of postpartum hemorrhage, probably due to early use of uterotonic agents (usually after delivery of the baby’s anterior shoulder). Examples of

Table 3–1 • ACTIVE MANAGEMENT VERSUS PHYSIOLOGIC MANAGEMENT OF THE THIRD STAGE OF LABOR
	Active Management	Physiologic Management
Uterotonic agents	None, or after placenta has delivered	With delivery of the anterior shoulder
Cord traction	None until clear signs of placental separation	Controlled cord traction when uterus contracted
Assessment of uterus	Uterine size and tone	Uterine size and tone

uterotonic agents include oxytocin, misoprostol, or ergotamine. Proponents of physiologic management of labor argue that there is less risk of entrapment of a retained placenta (due to difficulty with manual separation when uterotonic agents are given), and less chance of uterine inversion. There is currently no consensus of the best method.

COMPREHENSION QUESTIONS

3.1 A 23-year-old G1P0 woman at 38 weeks’ gestation delivered a 7 lb 4 oz baby boy vaginally. Upon delivery of the placenta, there was noted to be an inverted uterus, which was successfully managed including replacement of the uterus. Which of the following placental implantation sites would most likely predispose to an inverted uterus?

A. Fundal

B. Anterior

C. Posterior

D. Lateral

E. Lower segment

3.2 A 24-year-old woman underwent a normal vaginal delivery of a term infant female. After the delivery, the placenta does not deliver even after 30 minutes. Which of the following would be the next step for this patient?

A. Initiate oxytocin

B. Wait for an additional 30 minutes

C. Hysterectomy

D. Attempt a manual extraction of the placenta

E. Misoprostol estrogen intravaginally

3.3 A 32-year-old G1P0 woman at 40 weeks’ gestation undergoes a normal vaginal delivery. Delivery of the placenta is complicated by an inverted uterus, with subsequent hemorrhage leading to 1500 mL of blood loss. She is managed with a transfusion of erythrocytes. Which of the following is the best explanation of the mechanism of hemorrhage?

A. Inverted uterus stretches the uterus, causing trauma to blood vessels leading to bleeding.

B. Inverted uterus leads to inability for an adequate myometrial contraction effect.

C. Inverted uterus causes a local coagulopathy reaction to the uterus and endometrium.

D. Inverted uterus causes muscular abrasions and lacerations leading to bleeding.

3.4 A 33-year-old G5P5 woman, who is being induced for preeclampsia, delivers a 9 lb baby. Upon delivery of the placenta, uterine inversion is noted. The physician attempts to replace the uterus, but the cervix is tightly contracted, preventing the fundus of the uterus from being repositioned. Which of the following is the best therapy for this patient?

A. Vaginal hysterectomy

B. Dührssen incisions of the cervix

C. Halothane anesthesia

D. Discontinue the magnesium sulfate

E. Infuse oxytocin intravenously

3.5 A 25-year-old G1P0 woman delivers a 33-week infant vaginally. The delivery is uncomplicated. If the obstetrician wishes to optimize outcome for the infant, the cord should be clamped:

A. Immediately

B. Between 30 and 60 seconds

C. After 60 seconds

D. Leave the cord unclamped until delivery of the placenta

ANSWERS

3.1 A. A fundally implanted placenta predisposes to uterine inversion. A placenta implanted in either the anterior, posterior, lateral, or lower segment of the uterus does not have the direct angle that a fundally implanted placenta has through the cervix and out the vagina. The best method for preventing inversion is to await spontaneous separation of the placenta from the uterus before placing traction on the umbilical cord.

3.2 D. After 30 minutes, the placenta is abnormally retained, and a manual extraction is generally attempted. Waiting for another 30 minutes may lead to maternal hemorrhage, which may then lead to an indication for a hysterectomy. However, a hysterectomy would not be the initial step after 30 minutes have passed during the third stage of labor. Oxytocin should not be administered until the placenta has been delivered and the uterine fundus (when inverted) is placed back to its normal location. Oxytocin is a uterotonic agent that aids in allowing the uterus to contract down on itself in an effort to stop bleeding after the placenta has been removed. Intravaginal estrogen is not indicated for this scenario and is typically prescribed to patients with vaginal atrophy.

3.3 B. An inverted uterus makes it impossible for the uterus to establish its normal tone, and to contract. Thus, the myometrial fibers do not exert their normal tourniquet effect on the spiral arteries. The endometrial placental bed pours out blood, which previously had been perfusing the intervillous space. Thus, uterine atony is the most common reason for hemorrhage in inverted uterus. The muscle of the uterus and the vasculature is seldom damaged. Replacing the uterus to its normal position and assisting tonicity of the uterus will alleviate the bleeding.

3.4 C. A uterine relaxing agent (such as halothane anesthesia) is the best initial therapy for a nonreducible uterus. Terbutaline and magnesium sulfate can also be used to relax the uterus if necessary. Oxytocin is a uterotonic agent and may be used following replacement of the uterine fundus to its normal location. Dührssen incisions are used to treat the entrapped fetal head of a breech vaginal delivery and would not be indicated for uterine inversion. A vaginal hysterectomy would not be the best treatment option for this patient either.

3.5. B. Delayed cord clamping of between 30 and 60 seconds is beneficial for preterm infants due to increasing total iron stores and hemoglobin levels, and decreasing the risk of intraventricular hemorrhage in the infants. Immediate birth outcomes such as Apgar scores, umbilical cord pH, or respiratory distress is unaffected by the timing of cord clamping. Delayed cord clamping also improves iron stores in term infants, but may also lead to a higher risk of hyperbilirubinemia.

    CLINICAL PEARLS    

» Although it can occur spontaneously, one of the most common causes of inverted uterus is undue traction on the cord when the placenta has not yet separated. » The signs of placental separation are (1) gush of blood, (2) lengthening of the cord, (3) globular-shaped uterus, and (4) the uterus rising to the anterior abdominal wall. » Hemorrhage is a common complication of an inverted uterus due to uterine atony associated with inversion. » The upper limit of normal for the third stage of labor (time between delivery of the infant and delivery of the placenta) is 30 minutes. » When the placenta does not deliver spontaneously after 30 minutes, then a manual extraction of the placenta should be attempted. » There is current controversy about whether active management or physiologic management of the third stage of labor is best. » Active management of the third stage of labor seems to decrease the risk of postpartum hemorrhage.

REFERENCES

American College of Obstetricians and Gynecologists. Postpartum hemorrhage. ACOG Practice Bulletin 76. Washington, DC; American College of Obstetricians and Gynecologists; 2006. (Reaffirmed 2011.) 

Baskett TF. Acute uterine inversion: a review of 40 cases. J Obstet Gyneacol Can. 2002;24:953-57. 

Cunningham FG, Leveno KJ, Bloom SL, Gilstrap LC III, Hauth JC, Wenstrom KD. Obstetrical hemorrhage. In: Williams Obstetrics. 24th ed. New York, NY: McGraw-Hill; 2014:809-854. 

Kim M, Hyashi RH, Gambone JC. Obstetrical hemorrhage and puerperal sepsis. In: H acker NF, Gambone JC, Hobel CJ, eds. Essentials of Obstetrics and Gynecology. 5th ed. Philadelphia, PA: Saunders; 2009:128-138. 

You WB, Z ahn CM. Postpartum hemorrhage, abnormally adherent placenta, uterine inversion, and puerperal hematomas. Clin Obstet Gynecol. 2006;49:184.

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